1. Field of the Invention
The present invention relates generally to surveying and leveling and more particularly to a level or other survey device that can be controlled remotely to check compliance with a particular grade.
2. Description of the Prior Art
One of the major problems in earth-moving construction is to dig a hole with a flat bottom at a predetermined elevation (grade). For example when a back-hoe or other piece of large equipment is used to dig out a basement, swimming pool or other similar type of job, the result must be a level floor at exactly the right grade (height) to within a few fractions of an inch. Presently, a laser light emitter is mounted at the far rim of the hole that emits a level laser light beam. It is then necessary to send a person down into the hole to hold a pole with a laser detector or other height measuring instrument mounted on the top. The laser detector on the pole registers either high, low or level usually by a colored light, and up-down arrow and/or audible sound. A typical basement dig is shown in FIG. 1. A large excavator sits above the hole and digs toward itself. It is necessary for the laser detector on the pole to read level all over the bottom of the hold. Also, it is very undesirable to over-dig. Therefore, continuous height measurement of the flat bottom as digging progresses is essential.
The use of a human moving around the bottom of the dig presents a danger of an accident as well as the human possibly missing places or not holding the pole straight up and down. In addition, the present situation requires two people, both of which must be paid, or that the operator leave the excavator periodically, descend into the hole and make the measurement. It would be very advantageous to have a system and method that would 1) allow one person to complete the job alone, 2) provide a flat floor without the operator having to leave the digger, 3) minimize human error and danger.
In addition to digging basements and the like, there are many other survey and/or leveling type jobs that typically require two people. It would be advantageous to have a system and method that would allow one person to accurately complete these jobs. Some jobs are ideally suited for a remote-controlled survey unit such as paint spraying or other marking jobs, and digital straight line measurement for window wells and different features of construction.